Apparatus for sound reproductions



April 26, 1927. 6;088

J. J. JAKOSKY APPARATUS FOR SOUND REPRODUCTIONS Filed April 15. 1926 3Sheets-Sheet l 5 fig/ YwzziW p ATTOR EY A ril 192 p 7 .1. J. JAKQSKYAPPARATUS FOR SOUND REPRODUCTIONS 3 Sheets-Sheet 2 Filed April 15. 1926I EEP I I I da/w 38 A I ii J. J. JAKOSKY APPARATUS FOR- SOUNDREPRODUCTIONS April 26, 1927. 1,626,088

Filed April 15. 1926 5 Sheets-Sheet 3 A TT ORNE Y Patented Apr. 26,1927.

PATENT OFFICE.

JOHN J. JAKOSKY, OF IIOS'ANGELES, CALIFORNIA, ASSIGNOR' T INTERNATIONALPRECIPITATION COMPANY, OF LOS ANGELES, CALIFORNIA, A CORPORATION OFCALIFORNIA.

APPARATUS FOR SOUND RE PRODUCTIONS.

Application filed April 15,

This invention relates to the electrical reproduction of sound fromphonograph records andthe main object of the invention is to provide anadvantageous type of transmitting or reproducing device having meansadapted to hold a phonograph needle in position to engage the record andmeans for producing electrical impulses corresponding in frequency andintensity to the vibrating motion imparted to said needle by theundulations in the phonograph record. In the making of phonographrecords the cutting medium which engraves the undulations in the recordcorresponding to the sound to be recorded may be caused to vibrate in acertain direction, for example horizontally and transverse to thegrooves in the record, and in reproducing the sound ,from such record itis necessary that the needle of the reproducer be permitted to vibratein the same direction as the needle or-stylus used in recording and thatthe .reproducing device be adapted and connected for actuation by saidneedle so as to transmit electrical impulses corresponding to thevibration in this direction. It is possible during reproduction,however, that due to roughness or irregularity in the phonograph recordthe point of the needle may be moved or vibrated in other directionsthan that in which the principal vibration takes place. If suchvibrations of the needle in other directions are permitted to causeproduction of electrical impulses in the transmitting device the qualityof the reproduction is impaired since the electrical impulses soproduced cause sounds other 1 than those desired, and a considerablepartof the scratching sound ordinarily heard in phonograph reproductionis or may be due to vibrations of the needle in directions other thanthat corresponding to the direction of the major or intended vibrations.For example, in a phonograph record in which the undulationscorresponding to the sound to be reproduced occur in a horizontaldirection transverse to the grooves of the record, the scratching sound,may be due vibration or" the needle vertically or to vibration of theneedle longitudinally of the groove. important object of my invention isto provide a reproducing device of such construction that any vibrationims 1926. Serial No. 102,100.

set up electrical impulses in the transmitter or reproducer, Whilevibrations of such needle in any other direction will be eithermechanically prevented, suppressed, or damped, or Will be prevented fromactuating the transmitting device to cause production ofelcctricalimpulses. In such manner the sounds recorded on the record arereproduced with the utmost clearness and accuracy, while foreign soundsdue to mechanical scratching of the needle on the phonograph record orirregularities therein are entirely suppressed or reduced to a minimum.

The provision of a transmitter or reproducer which is sensitive orresponsive to vibrations in one direction only as above describedconstitutes an important object of my invention. The reproducer which Imay use for this purpose comprises preferably a rocking member mountedto rock only in one plane or "about one effective axis or fulcrum andprovided with means for carrying a phonograph needle or stylus inposition to engage the impressions of a phonograph record, the directionof the axis about which said member is mounted to rock being such thatsaid member is permitted to rock in response to motion of said needle inthe direction of the sound undulations in the record; means forresiliently resisting such rocking movement so as to damp the sameandtend to hold the rocking member in a certain equilibrium position;means for Wholly or substantially preventing rocking motion of saidrocking memberin any other directionv or about any other axis than thatdesired and for also Wholly or substantially preventing translativemotion of said rocking member; electromagnetic means; movahly mountedarmature means associated therewith; and link means connecting therocking member to the armature means so as to transmit the motion ofsaid rocking member only in the desired direction to the armature means.Not only is the motion of the rocking member in any other direction thanthat desired subst-anitally prevented, but also the link member is soconnected to the rocking member with respect to the points or places ofsupport of said rocking member that with respect to motion of saidrocking member in the desired direction theconnection thereof to thelink member is at an appreciable distance from the efi'ective fulcrum oraxis of the rocking member so as to provide an appreciable efi'ectivelever arm for transmittingmotion in this direction to the link mfin ber,while with respect to the motion of said rocking member in anotherdirection in which it is desired to suppress vibrations, the connectionof the link mem her to the rocking member is in line with orsubstantially in line with the effective fulcrum or axis of said rockingmember so as to provide no lever arm or substantially no lever arm fortransmitting rocking motion in this direction to the link member. Furthermore the link member is somewhat flexible but is sufiicientlyrigid to transmit motion in a. lengthwise direction and is so connectedto the rocking member and to the armature that the motion of the rockingmember which it is desired to transmit to the armature acts along thelength of the link member so that such motion is effectively transmittedto the armature means. The flexibility of the link member howeverrenders it incapable of effectively transmitting to the armature meansany motion of the rocking member in any other direction. The entiredevice is therefore highly selective with respect to the direction ofmotion which is transmitted from the phonograph needle to the armaturemeans.

A further object of my invention is to provide a transmitting devicewhich is aperiodic, that is to say, which has no natural period orfrequency of vibration, at which it tends to oscillate or vibrate withgreatly increased intensity, producing what may be termed blastingsounds. This is a defect which is found in diaphragms, and hence in theordinary mechanically reproducing phonograph or in any system in whichthe needle actuated mechanism comprises a diaphragm or other elementhaving a natural period of vibration. This 'object I accomplish bymaking the rocking member itself of the transmitting devicesubstantially rigid, and mounting the same on aperiodic resilientsupporting and damping means as hereinafter described.

The accompanying drawings illustrate embodiments of my intention andreferring thereto:

Fig. 1 is a vertical section of a cabinet provided with means forelectrical reproduction of phonograph records according to my invention.

Fig. 2 is a plan view of the apparatus shown in Fig. 1, with the coverof the cabinet removed.

3 is a section on line 33 in Fig. 2.

Fig. 4 is a section on line 44 in Fig. 3.

Fig. 8 is an inverted horizontal section on line 8-8 in Fig. 6.

Fig. 9 is a diagrammatic representation of an electrical amplifyingsystem suitable for use in connection with my invention. 7

Fig. 10 is a plan view of a device which I may use for making theelectrical connection between the transmitting device and the amplifyingsystem shown'in Fig.9.

Fig. 11 is a section on line 1111 in Fig. 10.

Fig. 12 is a plan view with the cabinet cover removed showing the'method of mounting the transmitting device on the tone arm of amechanically reproducing phonograph.

Fig. 13 is a partly sectional plan view showing in more detail themethod of mounting the transmitting device on the phonographtone arm.

Fig. 14 is a side elevation of the parts shown in Fig. 13.

F ig 15 is an inverted horizontal section similar to Fig. 8, showing amodified means of mounting the rocking member.

Fig. 16 is a section on line 16-16 in Fig. 15.

Referring to Figs. 1 to 3 the apparatus therein shown comprises acabinet 1 provided with horizontal partitions 2, and-3, and hinged cover4 serving to provide upper, middle, and lower compartments 5, 6, and 7within said cabinet. Within the upper compartment 5 there may beprovided a rotatably mounted record carrying plate or disk 8 whosevertical shaft 9 extends through partition 3 and is connected to drivingmotor indicated at 10 within the middle compartment 6. Said drivingmotor 10 may be either a spring motor or an electric 1no-' tor of anysuitable type ordinarily used in phonographs and may be provided withthe usual devices not shown for stopping and starting, for controllingthe speed thereof, for winding (in the case of a spring motor), etc. Thelower compartment 7 may be used for any suitable purpose. for exampleitmay be provided with a hinged door '11 at the front end thereof andmay be used for storing phonograph records in the usual manner. Thecabinet, record-carrying plate, driving motor, ete., above described mayconstitute parts of an ordinary phonograph provided with means formechanical production of sound, in which case the usual tone arm may besimply swung to one side or removed when my device is applied theretofor electrical reproduction; or the above parts may be provided solelyfor use in connection with my invention, in which case 29 when thetransmitting device is there is no need for provision of the usual tonearm and built-in horn.

A substantially horizontal carrying arm 14 may be mounted at a suitablepoint in the upper compartment of the phonograph so that it is adaptedto swing freely in a horizontal arc across and above the grooves of thephonograph record. For this purpose said arm may be provided with upperand lower bearings 15 and 16 engaging vertical shaft or rod 17 and mayalso hear on face plate 18 at the upper end of post 19 which extendsupwardly from a base member 20 mounted in any suitable manner onhorizontal partition 3. Arm 14 may be cut away as indicated at 21 so asto'permit it to swing horizontally without striking the vertical post19.

The transmitting or reproducing device indicated at 28 may comprise acylindrical casing 29 within which are mounted the parts hereinafterdescribed and said device may be provided with a pair of projecting lugs30 and may be pivotally mounted by means of said Lugs at the outer endof arm 14 so as to swing in a vertical plane. For this purpose a pin 31may extend through said lugs and through a similar pair of lugs 32 atthe end of arm 14. I prefer to provide means for decreasing theefi'ective weight of the transmiting device on the phonogra h needle;for example arm 14 may be provi ed with an interior recess and acounterweight arm'24-may also be mounted on pin 31 between the lugs andindependently of the reproducing device and may extend within recess 25.Pin 31 therefore serves as a common pivot means for the transmitting orreproducing device and for the counterweight 24. Said counterweight armmay be provided with'a shoulder 27- adapted to be engaged by the casinglowered intoposition on the phonograph record. By this means thetransmitting device may be raised ofi of the phonograph record andtilted back as indicated at 28 for'insertion of a new needle, etc.,during which movement said device swings free from the counterweight arm24 which simply falls to a position of rest at the bottom of. recess 25.hen, however, the transmitting device is lowered into playing positionthe rear face thereof engages shoulder 27 so as to lift thecounterweight arm from its position of rest and the counterweight armthen serves to reduce the effective weight of the transmitting deviceupon the needle or st lus. The counterweight arm 24 may be ma e of suchweight as to exert the desired counterplate and secured thereto, Iprovide apert ment of the balancing effect and give any desired prcsfrom the bri manent magnet 36 formed for example as a'ring' extendingaround inside of the casing 29 and having its two oppositely chargedends 37 and 38 overlapping but spaced from one another. U-shaped polepieces 39 and 41 may be secured to the respective ends 37 and 38 of saidmagnet and an armature42 may be mounted for rocking motion between saidpole pieces. Said armature may be mounted for example by means offlexible wires 43 and a light wire spring 44 may be so mounted as toexert a downward pressure on one end of said armature so as to preservea slight tension on the suspension wires 43.

Beneath the supporting late 34 is'mounted a substantially rigid rocl ingmember comprising for examplea bridge or plate 46 and a needle-carryingmember 47 integrally or rigidly secured to said bridge. The ends of thebridge 46 may be mounted between aperiodic resilient supporting pads orblocks 48 consistin for example of cylindrical pieces of rub er or otheryielding or resilientbut substantially aperiodic material and saidbridge may be clamped between said pads by means of suitable clampingmeans such as bolts 49 extending through said plate 34 and through saidpads and also passing loosely through openings 51 in bridge 46, saidbolts being provided at their lower ends with washers 52 and nuts 53.Said nuts may be tightened to any desired extent so as to cause thebridge '46 to be held-with the desired firmness between the resilientsupporting pads or blocks 48 and thus provide the desired dampingeffect, while permitting slight rocking movement thereof. The needlecarrying member 47 may be provided with a suitably shaped recess 56adapted to receive a phonograph needle or stylus 57 and a set screw 58may be rovided for securing said needle within sai recess. A link member59 may be secured .at its ends to armature member 42 and bridge member46, for example by soldering or otherwise, so as to transmit rockingmotion of bridge 46 to armature 42 as hereinafter described. In order topermit lengthwise adjustment of the link member with respect to therocking member, 1

said rocking member may be formed or novided with a bent-over portion 61exten ing back beneath and somewhat beyond the bridge 46 member may bentover portion. Said bent over be secured to the end of said portion has acertain amount of resiliency, and an adjusting screw 62 passes throughan-openand the lower end of said link ing therein and screws into themain portion of the bridgz, so as to. provide for adjustnt over portiontoward or away e. The effective length of the link member tween thearmature and the rocking member may thus be adjusted as desired so as toproperly space the armature between the pole-pieces 39 8.!!(1 41. l,

A wire coil 63 may be provided around the armature member 42 in suchmanner that changes in themagnetic flux in said armature member, due torocking motion thereof between the pole pieces 39 and 41, causeselectric currents or impulses to be set up within said coil.

A cover plate 64 may be provided for protecting the rocking member andother parts above described, said cover plate together with supportingplate 34 being secured to the ,casing 29 in any suitable manner. Said-er plate may have an opening 65 through ich the needle-carrying member47 proje cts and through which access may also be had to adjusting screw62.

Any suitable electrical amplifying means may be used for amplifying andtransmitting the electrical impulses set up in the above describedtransmitting device. Such amplifying means may comprise thermionicvacuum tubes 66 and 67 each provided with filament 68, grid 69, andplate 71, and may further comprise transformer 72 having its primarywinding connected to the plate of electrically o 4 able point within orconvenient v,reception of. radio messages, --comprising for 7 electricalimpulses 50 ing the volume of I means and the usual A, B, andCvbatteries for supplying the necessary electric current or voltagethereto. The amplifying system above described may be a separateamplifying system and may be located at any suitto the phonograph or itmay comprise the audiofrequency amplifying system of a radio receivingset. The coil 63 of the transmittin device may be connected by wires 76and 7 v t0 the filament and grid respectively of thermlonlc tube 66 anda rheostat or variable re- -A sistance means 78 may be included in oneof said wires for varying the strength of the therein-and henceadjustsound production.

When the amplifying means constitutes part of a radio receiving set theconnections may be made, as above described and as shown in fulllines inFig. 9, to the first audie-frequency amplifying 'tube; or if desired theconnections may be made, as indicated in dotted lines at. 76 and '77, tothe detector tube 79 of said radio receiving set. It will be understoodthat such radio receiving set may be provided with the usual means forexample antenna 81, groundvconnecti'on 82, primary and secondary coils83 and 84,.variable condenser and grid leak and cond er .86. The-a s eay e comprise transformer 87 having its primary winding connected to theplate of the detector tube 79 and its secondary winding connected to thegrid of the first amplifier tube 66, and the usual A and B batteryconnections may be provided. \Vhen the transmitting device is connectedto the grid circuit of the detector tube in this manner the detectortube is utilized as an additional amplifying tube, thus giving anadditional stage of amplification. It is to be noted that when thetransmitting device is so connected, the connection 77 is made betweenthe grid of the detector tube and the grid leak and condenser 86 so thatthe grid leak and the condenser serve to prevent the passage back intothe receiving circuit of practically all of the audio-frequency currentfrom the transmitting device and hence ensure said current beingconfined to the grid circuit of tube 79.

The wires 76 and 77 for connecting the transmitting device to theamplifying means may advantageously pass, as shown, through an opening89 in the side wall of the casing 29 of said transmitting device and maythen I pass through an opening 91 into the recess 25 within arm 14 andmay be carried back within said recess to the base ofsaid arm. Therheostat 78 may be located within base member 20 and the operating stemof said rheostat may constitute the vertical rod or shaft 17 about whicharm 14: swings, said shaft passing through said arm and being providedwith a button 79 for effecting ad'- justment of the rheostat. The wires76 and 77, may pass throu h an opening 81 in the base of arm 14 andthrough opening 82 in base member 3 and the rheostat may be connected toone of said wires so that the resistance thereof is inserted in 'saidwire. The wires 76 and 77 may then pass through openings 83 and 84 inthe cabinet and may be provided at their ends with suitable means forconnection to the amplifying system. 11 advantageous type of connectingmeans which I have devised for this purpose is shown in Figs. 10 and 11.The connecting member 86 therein shown may comprise a plug portion 87adapted to fit within a thermionic tube socket indicated in dotted linesat 104, and a socket portion 88 adapted to receive the base ofathermionic tube indicated in dotted lines at 105. The plug portionof'said connecting member may be provided with four contact pins 91, 92,93, and 94 which are ada ted to engage the usual contact elements of athermionic tube socket, and the socket portion of such connecting membermay be rovided with four contact members 95, 96, 9 and 98, which areadepted to engage the usual ins o'rlugs at the base of a thermionic tuandwhich are connected by wires99, 100, 101,1md 102 to the respe tivecontact pins 91 93, and

Inn

' other direction than that above described 94. The wires 76 and 77 mayextend through an opening 103 in the side of the connecting member 86and may be connected respectively to contact members 97 and 96 which areadapted to be engaged respectively by the negative filament and gridcontacts of the thermionic tube. Socket 88 may be provided with a slot106 adapted to receive the usual projecting pin or lug 108 of athermionic tube soas to provide a bayonet joint means between the tubeand'the socket, while plug 87 may be provided with a pin 107 adapted toengage slot 109 in the tube socket for Lafs'imilar purpose. In order toconnect the transmitting device to the thermionic tube of a radio set orother amplifying system by means of the connecting member abovedescribed, it is only necessary to remove from its socket the tube towhich the connection is to be made, and insert in such socket the plugportion 87 of said connecting member and then insert the tube in thesocket portion 88. Such tube is then connected in the circuit in exactlythe same manner as before and the necessary connections of wires 76 and77 are also provided.

In the operation of the above described apparatus a phonograph recordindicated at 111 is placed on the record-carrying plate 8 and is set inrotation at the proper speed by operation of motor 10 in the usualmanner.

The reproducing or transmitting device 28 is then lowered onto therecord so as to cause needle or stylus 57 to traverse the groove of therecord. The undulations in the groove of the record, which for use withthe particular reproducing device shown extend transversely with respectto the groove, cause the point of the needle to move rapidly back andforth in such direction and such motion of the needle causes rockingmotion of the bridge 46 about a horizontal axis perpendicular to. thedirection of cut of'the undulations in the record, such axis -beingindicated at 00-09 in Figs. 6 and 8. Such motion is then transmittedthrough link member 59 to armature 42. Said armature is thus caused tovibrate or rock about its midline.

It will be noted that the resilient supporting pads 48 tend to hold thebridge 46 in a certain normal position and resiliently damp the rockingmovement of said bridge about its effective axis m-w. Because of theaperiodicity or damping effect of the supportin pads the rocking memberhas -no' natura period of vibration and hence no tendency to oscillateat frequencies corresponding to sounds of certain pitches.

Furthermore the resilient supporting pads serve to substantially preventrocking movement of the rocking member in any and also substantiallyprevent translative vibration of said rocking member.

In the vibration of armature 42 the respective ends thereof are broughtalternate- .ly closer to and further away from the respective polepieces 39 and 41 so that an alternating magnetic flux is set up withinsaid armature. Small alternating or variable electrical impulses,corresponding in frequency and intensity to the vibration of well-knownand forms no essential feature,

of this invention. The operation of such amplifying. system is suchhowever as to produce within the loud speaker or sound producing means73 alternating current impulses corresponding to but of much greaterintensity than the electrical impulses initially set up in coil 63, andsuch amplified electrical impulses are utilized in the usual manner forthe operation of a diaphragm or other vibrating sound producing memberso as to produce sound of much greater volume and better quality thancan be produced by the ordinary phonograph diaphragm which ismechanically actuated by the needle.

Because of the elimination of oscillation or blasting in the reproducingor transmitting device, there is no blasting in the sound produced, andall notes or pitches are reproduced with substantially uniform accuracy.The result, when used for example in the reproduction of musicalselections, is much more pleasing and realistic than that obtained bythe use of a mechanically actuated diaphragm.

When it is desired to apply or utilize the H scribed, may be mountedupon a supporting and counterbalancing arm 116 which may be mounted atthe outer end of the tone arm 117 of the phonograph. Any suitable methodof mounting may be used for this ur ose de ending u on the construcp p pto w ich the device is 7 tion of the tone arm to be applied. I haveshown the device as applied in, connection with a tone arm which has atits outer end a laterally extending tubular portion 118 which, when usedas a mechanical reproducing phonograph, serves to receive one end of aU- shaped connecting tube to the other end of which is attached a soundbox. Such sound. box and U-shaped connecting tube may be removed and thestem or shaft 119 connected to arm 116 may be inserted within thetubular portion 118, said shaft being held in place for example by meansof retaining screw 120. The reproducing device may be pivotally mountedas at 121 on supporting arm 116 so as to swing vertically. When thetransmitting device is tilted backward for the purpose of changing theneedle the counterweight 122 at the other end of arm 116 may be loweredto rest on a supporting finger 123. When the transmitting device isre-lowered onto the phonograph record, however the rear face thereofengages shoulder 124 on anfi 116 so as to lift the counterweight fromits 0- sition of rest and decrease the effective weight of thetransmitting device on the needle. The connecting wires 76 and 77,contained for example he suitable cord or cable 126, may be carried backalong the tone arm and supported thereon in any suitable manner forexample by means of clamp 127 and may as before be connected to theamplifying system any suitable manner as by means of connecting member86'. The rheostat 78 which is connected in one of said wires may bemounted in any suitable position; for example it may be mounted as shownon the top of the tone arm near the base thereof.

Other means than that above described may be used for mounting therocking member of the transmitting device; for example as shown in Figs.15 and 16 the-bridge portion 46 of said rocking member may be mounted orheld at its ends between solid supporting pads 48 by means of clampingbrackets-130 which may be secured to the supportin plate 34 by means ofscrews 131. Raise points 132 may be provided, for example by the use ofa punching or upsetting tool, in supporting plate 34 and in clampingbrackets 130 in position to engage the centers of sup porting pads 48 soas to hold said pads firmly in position and the bridge member 46 may beprovided with openings or holes 133 also in position to be engaged bythe centers of supporting pads 48 so as to maintain the bridge member incentered position with-'re-' spect to said supporting pads. In this caseI have shown the bent over portion 61 of the bridge member, to which thelinkmember 59 is connected, as' extending above the bridge member ratherthan beneath the same, and adjusting screw 62 being provided as beforefor adjusting the relatlve'position of link member 59 and bridge, member46. The remainder of the construction may be r substantially the same asabove described and the manner of operation" thereof is alsosubstantially the same.

I claim:

1. In apparatus for sound reproduction, a transmitting device, memberprovided with phonograph needle, means supporting said rocking member soas to permit rocking movement thereof about one effective axis only,armature means mounted to vibrate, and flexible link means eonnectingsaid rocking member to said armature means in such manner as to transmitto said armature means rocking movement of said rocking member aboutsaid effective axis, and electromagnetic means associated with saidarmature means and adapted to produce current impulses corresponding tothe movements of said armature means.

2. A construction as set forth in claim 1, said. link means beingadjustably connected to said rocking member.

3. In apparatus for sound reproduction, a transmitting device,comprising a rocking member provided with means forcarrying a phonographneedle, means resiliently supporting said rocking member so as to permitrocking thereof in one plane about an effective axis, armature meansmounted to vibrate, electromagnetic means associated with said armaturemeans, and link means connected to .said rocking member at a pointremoved from said effective axis and. also connected to said armaturemeans, in such means for carrying a comprising a rocking manner as totransmit such rocking movemerit of the rocking member to said armaturemeans, the point of connection of said link member to said rockingmember being substantially in line with the efl'ective axis of saidrocking member with res t to rocking motion thereof in another p aneperpendicular to said first-named plane.

4. In an electrical phonograph reproducer, rigid supporting-means, arocking member provided with needle carrying means, resilient supportingand damping means between said rock ng member and said rigid sup portingmeans, additional resilientsupporting means at the other side of saidrocking member, and clamping means engaging sai additional resilientsupporting means and Secured to said rigid supporting means. so

as to clamp said rocking member between saidtwo resilient supportingmeans which constitute the sole support for said rocking member.

. 5. A construction as set forth in claim 4, and comprising in additiona magnet mounted on said" rigid supporting means, marmature mounted torock in the field of sajdg j magnet and a flexible link secured atitsento said armature and said rocking member respectively.

6. A construction asset forth claim and comprising in addition amagnetmonnted on said rigid supporting means, an armature mounted torock in the fieldof said magnet, a flexible link seeured at its ends tosaid armature and said rocking member respectively, and means foradjusting the effective length of said flexible link between saidrocking member and said'armatiire so as to pro ,erly space said armaturein the field of sai magnet. Y

In testimony whereof Ihave hereunto subscribed m name this. 6th day ofApril, 1926.

' 4 JOHN J. JAKOSKY.

